CVE-2021-21999 : Exploit Details and Defense Strategies

A local privilege escalation vulnerability has been identified in VMware Tools for Windows, VMware Remote Console for Windows, and VMware App Volumes.

Understanding CVE-2021-21999

This CVE-2021-21999 refers to a security flaw in VMware products that could allow an attacker to elevate their privileges on a compromised system.

What is CVE-2021-21999?

The vulnerability exists in VMware Tools for Windows, VMware Remote Console for Windows, and VMware App Volumes versions prior to specific releases. Attackers with normal access to a virtual machine can exploit this flaw by inserting a malicious file in an unrestricted directory to execute code with elevated privileges.

The Impact of CVE-2021-21999

Exploitation of this vulnerability could potentially lead to unauthorized access, data breaches, and further compromise of the affected systems. It poses a significant risk to the confidentiality, integrity, and availability of virtual environments.

Technical Details of CVE-2021-21999

The following key technical details outline the specifics of CVE-2021-21999:

Vulnerability Description

The vulnerability allows attackers to execute code with elevated privileges by placing a specially crafted file in a vulnerable directory.

Affected Systems and Versions

VMware Tools for Windows (11.x.y prior to 11.2.6), VMware Remote Console for Windows (12.x prior to 12.0.1), and VMware App Volumes (2.x prior to 2.18.10 and 4 prior to 2103) are impacted by this vulnerability.

Exploitation Mechanism

Attackers exploit this flaw by inserting a malicious file named `openssl.cnf' in a directory with elevated privileges, allowing them to execute arbitrary code.

Mitigation and Prevention

To safeguard your systems from CVE-2021-21999, consider the following mitigation strategies:

Immediate Steps to Take

Apply security updates provided by VMware to address the vulnerability promptly.
Restrict access to vulnerable systems and directories to authorized personnel only.

Long-Term Security Practices

Regularly monitor and audit file permissions and directory access controls.
Educate users and administrators on best practices for file handling and system security.

Patching and Updates

Ensure that VMware Tools for Windows, VMware Remote Console for Windows, and VMware App Volumes are updated to the latest versions that contain patches for CVE-2021-21999.